Process of obtaining sulfur from sulfids.



APPLICATION FILED JUNE 13, 191 3.

Patented Dec. 30, 1913.

. WILLIAM n. HALL, or NEW YORK, N. Y.

rnocnss or oisrnmme SULFUR FROM SULFIDS.

Specification of Letters I'atent.

Patented Dec. 30,1913.

Application filed June 13, 1913. Serial No. 773,456.

' c0vered certain new and useful Improvements in Processes of Obtaining Sulfur from Sulfids, of which the following is a specification, reference being had therein to the. accompanying drawings.

,In my copending application Serial No. 725,024, I have described and claimed a process of obtaining sulfur from metal sulfids such for example as pyrites, pyrrhotite and the like, by heating the same by the action of a reducing flame to a temperature maintained high enough to distil the sulfur, (between 700 and 900 0.), while introducing a. small amount of steam into contact with said sulfids, and also while agitating. the s'ulfid ore under .treatment. This treatment is preferably carried out in a mechanical, reverberatory, multiple shelf furnace, and

the conditions in each of the reaction zones may be about the same. 2

The present invention relates to an improvement on said process, in whichore is treated preferably in a furnace of the same general structure, but'in which the conditions maintained in the several compartments differ from each other.

In carrying out the process I may use a furnace constructed as shown in the annexed drawings, in which Figure 1 shows a. vertical section of the furnace, and- Fig.- 2 shows a horizontal section, on .the line AA of Fig. 1.

In operating in accordance with the present invention the metal sulfid, which may be pyrites or pyrrhotite or other metal sulfids is introduced from the hopper 1, lo-

cated over the top of the furnace into the first compartment. 2, -and thence passes through the opening 3, into'compartment 4, and so on downwardly to the several com-, partments 5, 6, 7, 8 and 9 of the furnace untilit reaches the outlet 10 whereit is discharged from the furnace.

' duced into the upper compartments through suitable pipes 12, and also may be intro- 'ment.

large amounts of H S are formed in the duced in smaller amounts into the lower compartments if desired, or may be omitted from these lower compartments.

On the upper shelves I maintain a very hlghly reducing flame, together with a-considerable amount of steam, in order to produce the largest amount of H S possible, and in each successive zone of the furnace the flame is maintained less reducing and a smaller amount of steam is admitted, until the sulfid reaches the lowermost part 9, where-it is treated with a flame which may be oxidizing and with a verysmall amount of steam, or none at all.

In the several compartments of-thefur nace are mounted any suitable rabbles 1 carried by the hollow shaft 15, which shaft may be air cooled if desired, and the rabbles may be air cooled or water cooled ifdesired. The temperature in the reaction zone 1 will in this manner be successively higher in each successive compartment, which temperature will preferably be about 700 C.

in the. uppermost compartments, while in the lower compartments the temperature is maintained considerably 'above 700 (3., and

may be up 115.900 C. in the last compart- As a result of this treatment very uppermost compartments, also a quantity. of free sulfur is distilled, while in the compartment near the middle a very large amount-of free sulfur is distilled while only a comparatively small amount of H S is produced or even 'no H 5 at all and in the lowermost;compartments considerable SO will alsobeformed if the flame is oxidizing.

lnstead 'b-fwallowing the-gases and vapors to pass principally upwardly through the furnaceas in my prior application above referred to, I findit preferable to withdraw from each of the compartments the major portion of the gases into a,suitable stand pipe or stack 16, from whence they are carried to suitable washing appliances for the recovery of the sulfur therefrom.

The principal reason for withdrawing as much as possible of the gases from each compartment is that these gases do not support combustion, but serve todilute the active atmosphere in each of the compartments,

' order to control the flow of the gases through these several flues, in such a manner that substantially all the gases produced in each compartment travel directly into the stack 16, and not into the next higher compartment of the furnace, as in my prior application above referred to.

In order to avoid too much false air being admitted into the furnace, I preferably maintain a very slight pressure (above atmospheric) within the furnace, although if thefurnace be reasonably tight, this precaution may not be necessary. The gases may be carried off from the stack 16 to the washers by means of any suitable pump located between said stack 16 and the washers, or located beyond the washers.

The removal of the sulfur content is much more rapid from the fresh ore than from the partially decomposed ore, and I find that the evolution of H 'S and free sulfur vapor in the uppermost compartments is very rapid.

' It will be noted that in this respect the present process differs from the process of any copending application in that in said application I seek to produce only a distillation of free sulfur and to keep down the formation of H 8 as much as possible, while in the present process I seek -to produce as much H S as possible, on all the upper shelves where I am distilling free sulfur, in order to utilize this H,S to combine with the S0 produced on the lower shelves, and which lower shelves I use to a considerable extent, the same as in the ordinary ore roasting process, and I find by repeated tests that the S0 produced in the latter part of the operation is very weak, and can all be deoxidized by the large'amount of H S produced in the earlierstages of the process. Accordingly I can run the upper shelves for the distillation of sulfur and the generation of H S and the lower shelves as an oxidizing or ore roasting operation, thereby generating S0 and mingling all the fumes together in one common stand pipe or flue. If desired I may also use air alone (Without any gas flames) on the lower shelves, although better results may be obtained by using some gas along with the air.

The method of producing H S and the furnace structure, are not claimed herein, since these form the subject matter of my copending applications 725,026, and 725,023, respectively, both filed Oct. 10, 1912.

That I claim is 1. A process of separating sulfur from sulfid ores, which comprises exposing said ores, in each of a plurality of successive steps, to the simultaneous action of a flame and of steam, the quality of the flame, as regards reducing power, being different, in thediiferent steps. 2

2. A process of separating sulfur, from sulfid ores, which comprises exposing said ore, in each of a plurality of successivesteps, to the simultaneous action of a flame and of steam, and quality of the flame, as regards reducing power, and the relative amount of steam employed, being different in the different steps.

3. A process, of separating sulfur from sulfid ores which comprises exposing said ores in each of a plurality of successive steps,'to the simultaneous action of a flame and of steam, the reducing power of the flame being less in the later steps, than in the earlier steps.

4:. A process of separating sulfur from a sulfid ore which comprises subject-ing said ore to a highly reducing flame and to a large amount of steam, then exposing said ore to a flame of less reducing power, and to a smaller amount of steam, and then exposing said ore to an oxidizing flame in the absence of material quantities of steam.

5. A process of separating sulfur from sulfid ores which comprises exposing said ores, in each of a plurality of successive steps, to the simultaneous action of a flame and of steam, the quality of the flame, as regards reducing power, being different in the different steps, and agitating said ore during said treatment.

6. A process of separatmg sulfur from sulfid ore which comprises subjecting said ore to a highly reducing flame and to a large amount of steam, then exposing said ore to a flame of less reducing power, and to a smaller amount of steam, and then exposing said ore to an oxidizing flame in the absence of material quantities of steam, and agitating the ore during each of said flame treatments.

7. A process of separating sulfur from sulfid ores, which comprises subjecting said ore, in a plurality of steps to the action of steam in different amounts, and to the action of flames of different reducing power, separately drawing off the gases and vapors evolved in said separate steps, and then conringling said gases to obtain sulfur therefrom.

8. A process of separatin sulfur from ores which comprises subjecting said ore to .the action of areducing flame and of steam,

1,083,251 v a r 3 the action of a reducing flame and of steam; in each of said steps, and mingling said 10 and thereafter subjecting said ore, while in gases and vapors together for obtaining free a heated state to oxidation. v sulfur. s

9. A process of separating sulfur from In testimony whereof I have atfixed my ores which comprises subjecting said ore to signature in presence of two witnesses.

, WILLIAM A. HALL. and thereafter subjecting said ore, while in Witnesses: a heated state to oxidation, and separately A. M. PERKINS, drawing off the gases and vapors produced M. R. MCKAY. 

